This invention relates to distillation equipment and to a process in which used automotive engine coolant may be effectively and economically distilled and then reused.
It is both environmentally and economically desirable to be able to reuse engine coolant. Old engine coolant contains contaminants that have damaging effects on the engine cooling system. Therefore, car manufacturers recommend the replacement of engine coolant at regular intervals. Engine coolant cannot be poured into the sewer because of its toxic nature. It must either be properly disposed or recycled. Some garages remove coolant, filter it, add "makeup" ethylene glycol and additional chemical inhibitors and return this coolant to service. Unfortunately, this is not a satisfactory procedure. The filtration does not remove nearly enough of the contaminants and since the coolant may have become diluted, some must be disposed of in the process of increasing the concentration of the coolant with fresh ethylene glycol or the like.
Distillation is a process which separates various compounds from a mixture by selective vaporization and condensation. The result is that the recovered compounds may be very pure. The temperature and pressure at which the vaporization takes place, as well as the composition of the mixture, controls composition of the vapor being removed from the mixture and the rate at which vaporization takes place.
Used engine coolant comprises two major components; namely, water and ethylene glycol. The remaining components, such as rust inhibitors, salts, silicates, metals and other undesirable contaminates are a very small but often very detrimental part of the overall volume.